/*
 * Copyright 2013-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.xd.analytics.metrics.metadata;

import javax.validation.constraints.AssertFalse;

import org.springframework.xd.module.options.spi.Mixin;
import org.springframework.xd.module.options.spi.ModuleOption;


/**
 * Captures options for the {@code rich-gauge} sink module.
 * 
 * @author Eric Bottard
 */
@Mixin(MetricNameMixin.class)
public class RichGaugeSinkOptionsMetadata {

	private double alpha = -1.0D;


	public double getAlpha() {
		return alpha;
	}

	@AssertFalse(message = "must be strictly between 0 and 1, or use -1 for arithmetic mean")
	public boolean isInvalidAlpha() {
		return alpha != -1 && (alpha <= 0.0 || alpha >= 1.0);
	}

	@ModuleOption("smoothing constant, or -1 to use arithmetic mean")
	public void setAlpha(double alpha) {
		this.alpha = alpha;
	}


}
